Abstract
The S-ROM®-A stem is a modular cementless hip implant with a modular proximal sleeve that mates with a fluted stem. The various sleeve and stem lengths, and proximal body types, can be configured into many combinations. Independence of the sleeve and stem permits correction of the excessive anteversion found in certain types of severe dysplasia in primary total hip arthroplasty (THA). We evaluated 18 severely dysplastic hips treated by THA using an S-ROM®-A stem between July 2005 and October 2007. Group I class was evident in 4 hips, group II class in 10 hips, and group III class in 4 hips according to Crowe’s classification. To determine the accuracy of the implant position, we calculated the change in the leg length, the anteversion of the acetabular and femoral neck, and femoral offset before and after the operation. We found that the S-ROM®-A stem offered a large range of femoral offset, length, and version options that could be used independently or in combination to recreate normal osseous anatomy and a well-tensioned soft tissue envelope, thus enhancing hip stability after THA for severely dysplastic hips.
